Analysis of PCDDs, PCDFs, planar and other PCBs in seaweed from Japanese coast

PCDDs, PCDFs, planar and other PCBs were analyzed by high resolution GC-MS in four species of seaweed collected from Japanese coast. Two different methods were examined for sample extraction. Soxhlet extraction from dried sample (method I) gave higher recovery than extraction from alkaline digested wet sample (method 2). PCDDS and related compounds were detected from all samples. It was suggested that seaweed analyzed in this study were contaminated by PCDDS and PCDFS of industrial origin such as combustion source, and the presence of natural dioxin could not be ascertained.